03.4 - Applied Aerodynamics
NUMERICAL CHARACTERISATION OF SHIP-AIRWAKE EFFECTS ON MEDIUM-WEIGHT UAV APPROACH AND GO-AROUND OPERATIONS TO CANBERRA-CLASS LHDS
M.J. Ericksen¹, N.J. Lawson¹; ¹The University of Sydney, Australia
The airwake environment in the lee of aircraft carriers and landing helicopter docks (LHDs) is highly unsteady and dynamically complex, posing significant challenges for aircraft operating at low airspeeds and reduced stall margins during approach and recovery. These challenges are amplified on ski-jump-equipped vessels, where the bow ramp acts as a dominant bluff body that generates strong separation, recirculation, and vortex structures extending across the near-deck and approach regions. While previous studies have examined ship airwakes near the flight deck and hover zones, the straight-in approach corridor aft of LHDs remains largely unexplored, particularly in the context of fixed-wing uncrewed aerial systems (UAS).rnThis paper presents a novel unsteady, full-scale computational fluid dynamics (CFD) investigation of the airwake generated by a Canberra-class LHD, with the objective of assessing its implications for the approach and recovery of medium-weight UAS up to 5,000 kg. A simplified ship geometry was simulated using an Improved Delayed Detached Eddy Simulation (IDDES) turbulence model within ANSYS Fluent. The numerical setup was verified through grid and temporal independence studies and validated against wind-tunnel experiments reported in the literature, demonstrating good agreement with key flow features and shedding characteristics.rnSimulations were conducted for ambient wind and ship speed combinations producing freestream wind velocities of 15–35 kt. Transient velocity and turbulence data were extracted along the approach, missed-approach, and landing corridors over a 20 s window representative of a nominal recovery. Detailed analysis of the 25 kt case reveals three dominant flow structures generated by the bow ramp: a strong asymmetric port-side vortex, a weaker starboard-side vortex, and an oscillatory central recirculation region that sheds turbulent “burbles” downstream along the deck centerline. The island supe
DOI: 10.71945/icas2026_0759